Starter switch for gaseous discharge devices



April 1, 1941 c. GHIRELSTEIN STARTER SWITCH FOR GASEOUS DISCHARGEDEVICES Filed June 25, 1940 Fig"? in U Ill.

? Z i 5 Z r 5 i maria; t'lakelsfiein, I N VE N TOR.

Patented Apr. 1, 1941 haired 2 caries.

STARTER SWKTCH FOR GASEQUS DISCHARGE DEVICES 9 Claims.

fhe invention here disclosed relates to switches for starting gaseousdischarge devices, such as fluorescent lamps and the like.

As at present constructed, the switches employed for this purpose havecertain serious faults. Because of the fact that the actual point ofcontact is microscopic and the peak voltage is high, the contact areasare destroyed in a relatively short time. With the form of electrodesused, the ionization lags. making the switch sluggish in action.Further, and particularly for the higher voltage tubes, resistors arerequired for controlling the ionization current.

Special objects of the present invention are to overcome and obviate theforegoing objections and limitations.

Further objects and advantages of the invention will appear in thecourse of the following specification.

In the drawing accompanying and forming part of the specification, onepractical commercial embodiment of the invention is illustrated, but itwill be understood that structure and composition of the actual physicalembodiment of the invention may be modified and changed in various waysall within the true intent and broad scope of the invention ashereinafter defined and claimed.

Fig. l is an enlarged and broken part sectional view of one of thecommercial embodiments of the invention.

Fig. 2 is a similar view looking at the switch from a different angle.

Fig. 3 is a cross-sectional view as on line 3-3 of Fig. 2.

The contacts of the switch are designated 5 and 6, the first being alooped bimetallic strip element arranged, on heating, to expand intoengagement with the second contact. The latter is shown in the form of arod or wire extending substantially parallel across the flat outer sideat the free end of the expanding strip contact, thus to provide forcircuit completing contact engagement across the full face width of thestrip.

With the structure and relation illustrated, full and complete circuitclosing contact is assured at all times, since the full width of thethermal strip is effective and utilized for circuit completing purposes.

The stationary contact 6 also is shown as having the end of the samebent over and across the free end portion of the movable switch elementat l, and as carrying the tab or plate 8, over the loop of the movableswitch element,

(or. zen-27.5

thus to provide more opposed electrode surface to facilitate ionizationand effect both faster operation and at lower voltage.

The rod i9, which carries the bimetallic switch element and the rod 6,which forms the companion switch contact are sealed at H, into theenvelope or container l2, and have connected with them external circuitwires H, l 3,

The case or so-called can for the glass envelope and the wiringterminals and insulating mounting for the same are not illustrated,since these accessories form no part of the present invention.

The gases used and pressures employed are important.

For a low voltage v.) glow switch neon and krypton in the proportions ofapproximately 99- 99%;% to 1 are preferred and for the socalled highvoltage (220 v.) switch helium is preierrecl. The use of helium in thehigh voltage switches eliminates any need for additional seriesresistors which have heretofore been found necessary and substantiallyincreases the ultimate life of the switch.

The best operating pressures for the low voltage neon-krypton gaseousswitches have been found to be about 4 to 6 centimeters and to be withinthe range of from 1 to 10 centimeters and the best pressure for the highvoltage helium switch as about 3 to 5 centimeters and within the rangeof from 1 to 6 centimeters.

The neon-krypton combination is a marked improvement over the neon andargon combinations now used in comparable starter switches and thehelium employed in the place of argon and resistor combinations,similarly, is an important advance over present practice in the highvoltage starter switches.

The starter switch disclosed may be used in the conventional circuitarrangements with the switch connected in an auxiliary starter circuitacross the outer ends of the tube filaments, that is, those ends whichare not connected with the power circuit.

What is claimed is:

1. A starter switch for gaseous discharge devices, comprising a gaseouscontainer, a bowed flat strip of bimetallic material supported at oneend in said container with the opposite end free to move under thermalexpansion of the strip and a fixed switch contact rod in said containerdisposed at an angle to the longitudinal extent of said bimetallic fiatstrip and extending in substantially parallel relation across the fullwidth of the fiat face of said strip at the free end of the same and anangular extension at the end of said rod contact projecting in spacedrelation across the edge portion of said bowed bimetallic contact.

2. A starter switch for gaseous discharge devices, comprising a gaseouscontainer, a bowed fiat strip of bimetallic material supported at oneend in said container with the opposite end free to move under thermalexpansion of the strip and a fixed switch contact in said containerextending in substantially parallel relation across the full width ofthe fiat face of said strip at the free end of the same and an electrodeplate carried by said fixed switch contact and projecting in spacedrelation across the bowed portion of said flat strip.

3. A starter switch for gaseous discharge de-v vices, comprising agaseous container, 2. bowed fiat strip of bimetallic material supportedat one end in said container with the opposite end free to move underthermal expansion of the strip and a fixed switch contact in saidcontainer extending in substantially parallel relation across the fullwidth of the fiat face of said strip at the free end of the same andsaid fixed switch contact having an end portion extending angularlyacross the edge of said bowed switch contact.

4. A starter switch for gaseous discharge devices, comprising a sealedenvelope, a mixture of neon and krypton in said envelope inapproximately the proportions 9999 /2% to /21% and cooperativethermostatic switch elements sealed in said envelope.

5. A starter switch for gaseous discharge devices, comprising a sealedenvelope, a filling of rare gas including neon and krypton at a pressureof 4 to 6 centimeters in said envelope, an expansive thermostatic switchelement sealed in said envelope and a companion switch element sealed insaid envelope, said cooperating switch elements having extensive opposedand coacting multiple contact areas.

6. A starter switch for gaseous discharge devices, a filling of rare gasincluding neon and a small proportion of krypton in said envelope undera pressure within the range from 3 to 6 centimeters and a thermostaticswitch sealed in said envelope.

'7. A starter switch for gaseous discharge devices, comprising a sealedenvelope, a mixture of neon and krypton in said envelope under apressure within the range of 4 to 6 centimeters and a thermostaticswitch sealed in said envelope.

8. A starter switch for gaseous discharge devices, comprising anenvelope, an atmosphere of rare gas including neon and a smallproportion of krypton sealed in said envelope under pressure of between1 to 10 centimeters and a thermostatic switch sealed in said envelope.

9. A glow switch for gaseous discharge devices, comprising an envelope,an ionizing atmosphere sealed in said envelope, a bowed bimetallic flatstrip contact supported at one end in said envelope, a fixed switchcontact in said envelope extending in normally spaced relation acrossthe flat surface of the free end portion of said bowed contact and aplate in angularly projecting relation on the end of said fixed contactand in opposition to the bowed edge portions of said bimetallic contact.

CHARLES CHIRELS'I'EDT.

